Today's market demands software developed at internet speeds, and Scrum is the magic silver bullet that delivers. Based on interchangeable faceless engineers performing at consistent top velocity and colourful, simplistic graphics that even a top manager can understand at a single glance, new web pages can be delivered at web scale in little to no time with a minimal commitment.
Of course, the elephant in the room is that 80% of all software development is maintenance (remember, every line of code typed by a trained monkey enters maintenance immediately). Also, a web page or other UI veneer is only the top of the iceberg of software development and accounts for maybe 1% of software.
So, while Scrum and other rigid Agile product are great for a lot of managers to grasp because of the slick webinar presentations so readily available while playing that red jack on the black queen, the reality is they don't really deliver. Turns out there is no easy substitute for good planning and effective management for any task of more than basic complexity.